The present invention relates to a spacer or spacing sleeve for the spacing of two parts, in particular for spacing two hollow gearbox shafts that can rotate with respect to each other.
When coupling together two hollow gearbox shafts which rotate relative to each other, it is known to use piston rings to control the relative axial position of the shafts. For example, such piston rings are installed in a radial groove in one of the hollow shafts. In the assembled condition the outer circumferential surface of the piston rings is in contact with the second hollow shaft. Since the position of the piston rings cannot be inspected visually during assembly, an unintended shearing of the piston ring is frequently not discovered during assembly, but only after problems develop during operation. Another disadvantage in the use of piston rings is that with increasing diameter of the rings the power loss due to friction climbs rapidly.
If a sleeve-type spacer element is used to maintain a desired spacing between the relatively rotating parts, then surfaces of the spacer sleeve will frictionally engage corresponding surfaces of the relatively rotating parts. For example, an outer surface of the sleeve will contact a corresponding inner bore surface of one the parts, and end faces of the sleeve will engage corresponding axially facing surfaces on the parts.